When the H flume was developed, analysis of the stage-to-discharge data showed that the flows could be characterized by three different equations:  low flow, transitional flow, and main flow.  Using those equations, though, was difficult in the field – and flow tables were usually used instead.   While Bos et al reduced these to a single equation, the equation was cumbersome to use in the field.

To simplify things, Teledyne Isco developed single variable discharge equations for H flumes (but not HS or HL flumes) for the 8th edition of their Open Channel Flow Measurement Handbook.  These equations are intended to provide the discharge rate over the main flows for each flume. The simplified equations may over / under estimate flow at the lower / upper ranges of flows.

0.5-Foot H Flume
	CFS (ft) = 1.71*H^2.31
	GPM (ft) = 767.4*H^2.31
	MGD (ft) = 1.12*H^2.32
0.75-Foot H Flume
	CFS (ft) = 1.84*H^2.31
	GPM (ft) = 830.3*H^2.31
	MGD (ft) = 1.196*H^2.31
1.0-Foot H Flume
	CFS (ft) = 1.95*H^2.31
	GPM (ft) = 875.2*H^2.31
	MGD (ft) = 1.26*H^2.31
1.5-Foot H Flume
	CFS (ft) = 2.11*H^2.31
	GPM (ft) = 947*H^2.31
	MGD (ft) = 1.36*H^2.31
2.0-Foot H Flume
	CFS (ft) = 2.32*H^2.31
	GPM (ft) = 1,000.8*H^2.31
	MGD (ft) = 1.44*H^2.31
3.0-Foot H Flume
	CFS (ft) = 2.41*H^2.31
	GPM (ft) = 1081.6*H^2.31
	MGD (ft) = 1.56*H^2.31
4.5-Foot H Flume
	CFS (ft) = 2.6*H^2.31
	GPM (ft) = 1166.9*H^2.31
	MGD (ft) = 1.68*H^2.31

 

Image:  Fondriest Environmental